DIFFERENTIAL DEMONSTRATION OF MUSCLE AND HEART TYPE LACTIC DEHYDROGENASE OF RAT MUSCLE AND KIDNEY

Abstract

A method for the histochemical demonstration of lactic dehydrogenase (LDH) is presented. This method utilizes a semipermeable membrane to minimize enzyme diffusion and high tetrazole concentration with a controlled reaction rate to minimize product diffusion. It was demonstrated that phenazine methosulfate could be used to make the reaction independent of endogenous diaphorase providing either a cytochrome oxidase inhibitor or strict anaerobiosis is employed. Differentiation of cells containing predominantly H-LDH from cells containing predominantly M-LDH was achieved by the use of 4 molal urea or pyruvate in the incubation medium. A preliminary report of the staining patterns observed in rat gastrocnemius and kidney indicates the usefulness of the technique. A new avenue to the study of the distribution of the LDH subunits is thus opened.